The constant search for cost cutting in the manufacturing and assembly stages for all the components of a vehicle as such is well known in the vehicle manufacturing industry. With respect to the assembly stage, this stage requires qualified workers, who are generally located on an assembly line, where they assemble the corresponding parts of the vehicle onto the chassis of a vehicle.
Namely, in said assembly phase, one of the stages relates to the assembly of the inner panels of the vehicle, coupled to the bodywork panels of the vehicle; and where this step is currently performed as follows:                The worker receives one of the panels to be assembled, where said panel has been previously perforated in order to introduce the corresponding joining devices.        The worker inserts the respective joining screws through the openings and from only one side of the panel.        Subsequently, another worker located at the other side of the panel then places another panel that rests on the screws, in order to then thread a nut onto each screw and therefore make the joining devices fasten and assemble the corresponding panels.        
This procedure thus requires two workers or machines, depending on the automation of the assembly line, where one inserts a screw into the panel on one side and then another worker couples the other panel and proceeds to assemble the whole by tightening the corresponding nut.
One of the possible solutions in order to save assembly costs is that of reducing the cost of the fastening device, where we currently have a device consisting in a screw and a nut, preferably made in plastic materials, since:                The material is cheaper to shape with respect to the cost of metallic materials;        the material is lighter and therefore reduces the total weight of the vehicle, increasing its performance and reducing consumption; and        the material is more elastic and allows filtering possible vibrations generated in the body.        
But the savings on the device itself do not involve very important savings with respect to the costs in investment in order to reduce its manufacturing cost.
Therefore, the other possible solution considered is reducing the cost of the assembly procedure and the coupling of the respective panels in order to reduce the assembly stages and manage to reduce the price of the total cost of the corresponding vehicle; and it is therefore necessary to invent a new procedure protocol for panel assembly and a new device associated to the procedure which allows reducing assembly times and also saving time and preventing handling risks and the need of the worker to travel about the work area.